JP2000267979A - Storage system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize multiplexing and hierarchization of a storage device with simpler structure and to simultaneously reduce overhead due to multiplexing. SOLUTION: Respective frames of a storage area securing request, a data writing request, a data reading request and a storage area releasing request based on a network protocol are issued to storage devices 701, 702, 703 by broadcast or multicast via a LAN 801 by a central processing unit 101 of this storage system. The frames of respective requests are received via the LAN 801, securing of the storage area, writing of data in the storage area, reading of the data from the storage area and release of the storage area are performed and respective frames of response to securing of the storage area, response to writing of the data, response to reading of the data and response to release of the storage area based on the network protocol are returned to the central processing unit 1 via the LAN by the storage devices 701, 702, 703.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage system, and more particularly, to a central processing unit and a plurality of storage devices connected to a LAN.
The present invention relates to a storage system in a computer system connected via a (Local Area Network).

[0002]

2. Description of the Related Art Conventionally, a central processing unit and a storage device are LA
In a computer system connected via N, data is exchanged between a central processing unit and a storage device using a network protocol as a communication protocol. This has been realized by copying data to a plurality of storage devices using a dedicated multiplexing device or by the central processing unit individually issuing data write requests to the plurality of storage devices.

Conventionally, in a computer system in which a central processing unit and a storage device are connected via a LAN, the storage devices are hierarchized by using different transmission paths and procedures between the storage devices of each hierarchy. It had been.

A technique for connecting the inside and outside of a system by a communication protocol and transferring data by copying via a shared memory is disclosed in Japanese Patent Application Laid-Open No. 8-339354 as "Network Distributed Processing System". No consideration has been given to multiplexing and layering of stored data.

A technique for realizing interface transparency through a communication connection is disclosed in Japanese Patent Application Laid-Open No. 7-44290 as "System Control System and Apparatus". Hierarchy was not considered.

[0006]

In the above-described conventional technique of multiplexing stored data, the configuration of the storage system becomes complicated, and performance is sacrificed due to overhead (performance degradation due to dead time) due to multiplexing. There was a problem of doing. The reason is that the data is copied to a plurality of storage devices using a dedicated multiplexing device, or the central processing unit issues a data write request individually to the plurality of storage devices to store the data. This is because multiplexing has been realized.

[0007] Further, the conventional technique of hierarchically storing data has a problem that the storage system becomes complicated.
The reason is that hierarchies of storage devices have been realized by using different transmission paths and procedures between storage devices in each hierarchy.

A first object of the present invention is to provide a storage system which realizes multiplexing of storage devices with a simpler configuration and reduces overhead due to multiplexing.

A second object of the present invention is to provide a storage system which realizes a hierarchical structure of storage devices with a simpler configuration.

[0010]

SUMMARY OF THE INVENTION A storage system according to the present invention is a computer system in which a central processing unit and a plurality of storage devices are connected via a LAN. By transmitting / receiving a reservation response frame, a data write request frame, a data write response frame, a data read request frame, a data read response frame, a storage area release request frame, and a storage area release response frame via a LAN by broadcast or multicast, It is characterized in that multiplexing and layering of storage devices are realized.

In a storage system according to the present invention, in a computer system in which a central processing unit and a plurality of storage devices are connected via a LAN, the central processing unit may include a storage area reservation request frame based on a network protocol.
A data write request frame, a data read request frame, and a storage area release request frame are issued to the plurality of storage devices by broadcast or multicast via a LAN, and the plurality of storage devices send a LAN from the central processing unit. Receiving a storage area reservation request frame, a data write request frame, a data read request frame, and a storage area release request frame, and secures a storage area, writes data to the storage area,
The CPU reads data from the storage area and releases the storage area, and processes the storage area reservation response frame, the data write response frame, the data read response frame, and the storage area release response frame based on the network protocol via the LAN. The multiplexing of the plurality of storage devices is realized by sending a reply to the device.

Further, a storage system according to the present invention is a computer system in which a central processing unit, a storage unit having a high speed level, and a storage unit having a low speed level are connected via a LAN. A storage area securing request frame, a data write request frame, a data read request frame, and a storage area release request frame based on a network protocol are issued to the storage device having the higher speed level via the LAN. A storage area reservation request frame, a data write request frame,
Receives a data read request frame and a storage area release request frame, secures a storage area, writes data to the storage area, reads data from the storage area, and releases the storage area. A secure response frame, a data write response frame, a data read response frame, and a storage area release response frame are returned to the central processing unit via the LAN, and the status of access to the storage area of the own apparatus is monitored for a predetermined time. When there is a storage area to which no access is made, the storage area reservation request frame and the data write request frame based on the network protocol are set to L.
Issuing data to the low-speed storage device via the AN to cache the data; and when accessing the low-speed storage device to the cached data, a data read request frame based on a network protocol. And issues a storage area release request frame to the storage device having the lower speed level via the LAN to cache data therein, and the storage device having the lower speed level stores the data from the storage device having the higher speed level via the LAN. Receives an area reservation request frame, a data write request frame, a data read request frame, and a storage area release request frame, and secures a storage area, writes data to the storage area, reads data from the storage area, and reads the storage area. Release and record based on the network protocol. By returning an area reservation response frame, a data write response frame, a data read response frame, and a storage area release response frame to the storage device having the higher speed level via the LAN, the storage device having the higher speed level and the speed level are returned. In which a hierarchy with a storage device having a low level is realized.

Still further, the storage system of the present invention comprises a central processing unit, a plurality of storage units having high speed levels,
In a computer system in which a storage device having a low speed level is connected via a LAN, the central processing unit includes a storage area reservation request frame, a data write request frame, a data read request frame, and a storage area release request based on a network protocol. A frame is issued to the plurality of storage devices having a high speed level by broadcast or multicast via a LAN, and the plurality of storage devices having a high speed level are transmitted from the central processing unit to a storage area reservation request frame via the LAN. Receiving a data write request frame, a data read request frame, and a storage area release request frame, and secures a storage area, writes data to the storage area, reads data from the storage area, and releases the storage area. Network protocol Brute storage area allocation response frame,
A data write response frame, a data read response frame, and a storage area release response frame are returned to the central processing unit via the LAN, and the access status of the storage area of the own apparatus is monitored, and there is no access for a predetermined time or more. When there is a storage area, a storage area securing request frame and a data write request frame based on a network protocol are issued to the storage device having the lower speed level via the LAN to cache out data, and the storage device having the lower speed level is provided. Issue a data read request frame based on a network protocol and a storage area release request frame to the low-speed storage device via the LAN when the cached-out data is accessed, and cache the data; The speed level is low The storage device receives a storage area reservation request frame, a data write request frame, a data read request frame, and a storage area release request frame from the plurality of high-speed storage devices via the LAN, and reserves the storage area. Writes data to the storage area, reads data from the storage area, and releases the storage area. A storage area reservation response frame, a data write response frame, a data read response frame, and a storage area release response frame based on a network protocol. Is returned to the plurality of high-speed storage devices via the LAN, thereby realizing multiplexing of the plurality of high-speed storage devices, and the plurality of high-speed storage devices. Achieved tiering with storage devices with low speed levels And it features.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a computer system which implements a storage system according to one embodiment of the present invention. This computer system includes a central processing unit 10
1 and three storage devices 701, 702, 703 are L
It is configured to be connected in parallel via AN801.

The central processing unit 101 includes an arithmetic unit 201,
And a network control unit 301.

The operation unit 201 includes storage devices 701 and 70
A request to secure a storage area, a request to read data, a request to write data, and a request to release a storage area to the network control unit 301 are transmitted to the network control unit 301.

The network control unit 301 responds to a storage area reservation request, a data read request, a data write request, and a storage area release request by using a storage area reservation request frame, a data read request frame, a data write request frame, And a storage area release request frame is created on the buffer 311 and the frame created on the buffer 311 is broadcast (broadcast) or multicast (selective broadcast)
To the LAN 801. In addition, the network control unit 301 receives a storage area reservation response frame, a data read response frame, a data write response frame, and a storage area release response frame based on a network protocol on the buffer 311 via the LAN 801.

The storage devices 701, 702, 703 include network control units 401, 402, 403, conversion tables 501, 502, 503, and storage units 601, 602,
603 respectively. Here, it is assumed that the storage devices 701 and 702 have the same response speed and are set to the speed level 1. In addition, the storage device 703
Is set to the speed level 2 having a lower response speed than the storage devices 701 and 702.

Network controllers 401, 402, 40
3 is a buffer 411, 412, 413 and an arbiter 4
21, 422, and 423.

The buffers 411, 412, and 413 temporarily store the storage area reservation request frame, the data write request frame, the data read request frame, and the storage area release request frame transmitted from the central processing unit 101 via the LAN 801. A storage area reservation response frame for storing and returning from the storage devices 701, 702, and 703 to the central processing unit 101 via the LAN 801;
This area temporarily stores a data write response frame, a data read response frame, and a storage area release response frame.

The arbiters 421, 422, and 423 are LA
It plays a role of arbitrating (contention control) the request for securing the use right of N801.

The conversion tables 501, 502, 503 are
The global addresses specified in the storage area reservation request frame, the data write request frame, the data read request frame, and the storage area release request frame are stored in the storage units 601 and 60 of each of the storage devices 701, 702, and 703.
This is a table to be converted into a local address unique to 2,603.

FIG. 2 shows the conversion tables 501, 502, 5
It is a figure which illustrates the content in 03. Referring to FIG.
Each record of the conversion tables 501, 502, and 503 is
A global address (start global address and area size) in the computer system designated by the central processing unit 101 and a local address (start local address and area size) in the storage units 601, 602, and 603.
And a status indicating the state of the storage area (non-shared with other storage devices: clean, shared: shared, invalid: invalidate, unused: free).

Referring to FIG. 3, the storage area reservation request frame includes a source port number, a destination port (broadcast), a header length, a checksum, a command (storage area reservation), a start global address, an area size, and a request count. Consists of a severe / requested speed level.

Referring to FIG. 4, the storage area reservation response frame includes a source port number, a destination port (broadcast), a header length, a checksum, a response (storage area reservation), a starting global address, an area size, and a response speed. Consists of levels.

Referring to FIG. 5, the data write request frame includes a source port number, a destination port (broadcast), a header length, a checksum, a command (data write), a start global address, an area size, and data. In this embodiment, it is assumed that variable-length data transfer is possible and that there is no data transfer exceeding the data length limit of the network protocol. That is, the data size (area size) of the data read request and the data write request requested by the central processing unit 101 at one time does not exceed the data length limit of the network protocol, and one data transfer is within one frame. I do.

Referring to FIG. 6, a data write response frame includes a source port number, a destination port (broadcast), a header length, a checksum, a response (data write), a start global address, an area size,
And unused.

Referring to FIG. 7, the data read request frame includes a source port number, a destination port (broadcast), a header length, a checksum, a command (data read), a starting global address, an area size, and unused. .

Referring to FIG. 8, a data read response frame includes a source port number, a destination port (broadcast), a header length, a checksum, a response (data read), a start global address, an area size,
And data.

Referring to FIG. 9, the storage area release request frame includes a source port number, a destination port (broadcast), a header length, a checksum, a command (storage area release), a start global address, an area size, and Consist of use.

Referring to FIG. 10, the storage area release response frame includes the source port number, destination port (broadcast), header length, checksum, response (storage area release), start global address, area size, and Consist of use.

Referring to FIG. 11, the central processing unit 101
The processing at the time of the storage area reservation request in the network control unit 301 of the first embodiment is performed in the storage area reservation request frame creation step S
101 and storage area reservation request frame sending step S1
02 and storage area reservation response frame receiving step S10
3 and a storage area securing recognition step S104.

Similarly, referring to FIG.
01 and 702 when receiving the storage area reservation request, the storage area reservation request frame receiving step S201, the conversion table search step S202, and the storage area reservation step S203.
And storage area reservation response frame creation step S204
And a storage area reservation response frame transmission step S205. The processing at the time of receiving the storage area reservation request in the network control unit 403 of the storage device 703 is exactly the same.

Referring to FIG. 12, the central processing unit 101
The process performed by the network control unit 301 at the time of a data write request includes a data write request frame creation step S301, a data write request frame transmission step S302, a data write response frame reception step S303, and a data write recognition step S304.

Similarly, referring to FIG.
No. 01, 702 when the network control unit 401, 402 receives a data write request includes a data write request frame receiving step S401, a conversion table search step S402, a data write step S403 in a storage area, and a data write response frame. It comprises a creating step S404 and a data write response frame sending step S405. The processing at the time of receiving a data write request in the network control unit 403 of the storage device 703 is exactly the same.

Referring to FIG. 13, the central processing unit 101
The process performed by the network control unit 301 at the time of a data read request includes a data read request frame creation step S501, a data read request frame sending step S502, a data read response frame receiving step S503, and a read data acquisition step S504.

Similarly, referring to FIG.
01, 702 when the data read request is received includes a data read request frame receiving step S601, a conversion table search step S602, a data read step from the storage area S603, and a data read response frame. It comprises a creation step S604 and a data read response frame transmission step S605. The storage device 703
The processing at the time of receiving a data read request in the network control unit 403 is exactly the same.

Referring to FIG. 14, the central processing unit 101
The processing at the time of the storage area release request in the network control unit 301 is performed in the storage area release request frame creation step S
701 and storage area release request frame sending step S7
02 and storage area release response frame receiving step S70
3 and a storage area release recognition step S704.

Similarly, referring to FIG.
01, 702 at the time of receiving the storage area release request, the storage area release request frame receiving step S801, the conversion table search step S802, and the storage area release step S803.
And storage area release response frame creation step S804
And a storage area release response frame transmission step S805. The processing at the time of receiving the storage area release request in the network control unit 403 of the storage device 703 is exactly the same.

Referring to FIG. 15, the storage devices 701, 7
The outline of the process at the time of cache out in the network controllers 401 and 402 of No. 02 is as follows: a storage area reservation request frame sending step S901, a storage area reservation response frame receiving step S902, a data write request frame sending step S903, and a data write response. Frame receiving step S904 and storage area releasing step S9
04.

Similarly, referring to FIG.
The outline of the process at the time of cache-out in the network control unit 403 of No. 03 includes a storage area securing request frame receiving step S1001 and a storage area securing step S100.
2 and storage area reservation response frame transmission step S100
3, a data write request receiving step S1004,
It comprises a step S1005 of writing data to the storage area and a step S1006 of sending a data write response frame.

Referring to FIG. 16, the storage devices 701, 7
The outline of the process at the time of cache-in in the network control units 401 and 402 of the storage area 02 is as follows.
1101, a data read request frame transmission step S1102, a data read response frame reception step S1103, a data write to storage area step S1104, a storage area release request frame transmission step S1105, and a storage area release response frame reception step S1106. , And a storage area release recognition step S1107.

Similarly, referring to FIG.
The outline of the process at the time of the cache-in in the network control unit 403 of No. 03 includes a data read request frame receiving step S1201, a data read from the storage area step S1202, a data read response frame sending step S1203, and a storage area release request frame reception step. Step S1204 and storage area release step S12
05 and storage area release response frame transmission step S12
06.

In the storage system according to the present embodiment, one frame is transmitted by using broadcast (broadcast) or multicast (selective broadcast) as a network protocol at the time of a request from the central processing unit 101. Transmission of a plurality of storage devices 701,
Requests can be sent to 702 and 703 simultaneously. In other words, the network control unit 40 can perform one frame transfer.
1, 402 and 403 can be simultaneously informed of the request.

Next, the operation of the storage system thus configured according to the first embodiment will be described.

(1) First, a storage area reservation request from the central processing unit 101 to the storage devices 701, 702, and 703 will be described.

In the central processing unit 101, the arithmetic unit 201
In order to secure a storage area for the storage devices 701, 702, and 703, the source port number, destination port (broadcast), header length, checksum, command (storage area reservation), start global address, and area size , And a storage area reservation request including the requested multiplicity / requested speed level is transmitted to the network control unit 301.

The network control unit 301 includes the arithmetic unit 20
When the storage area reservation request is transmitted from the server 1, a storage area reservation request frame (see FIG. 3) based on the network protocol is created in the buffer 311 (step S10).
1), the storage area reservation request frame created on the buffer 311 is transmitted to the LAN 801 by broadcast (broadcast communication) or multicast (selective broadcast communication) (step S102).

In the storage devices 701, 702, and 703, the arbiters 421, 422, and 423 arbitrate requests for securing the right to use the LAN 801.

When the requested multiplicity in the storage area securing request frame from the central processing unit 101 is 1 and the requested speed level is 1, one of the storage devices 701 and 702 is used. Only the storage device that has responded first should reserve the storage area, and the other storage devices stop responding and do not reserve the storage area.

Now, the storage device 70 is operated by the arbiter 421.
1 obtains the right to use the LAN 801, the network control unit 401 of the storage device 701
, And temporarily stores it in the buffer 411 (step S201).

Next, the network control unit 401 extracts the command (storage area reservation), the starting global address, and the area size from the storage area reservation request frame temporarily stored in the buffer 411, and
It is determined whether or not there is a corresponding free storage area in the storage unit 601 with reference to 01 (step S202).

If there is a corresponding free storage area in the storage unit 601, the network control unit 401 secures a storage area of an area size from the start global address in the storage unit 601, and also stores the start global address, start local address, and status. Is generated in the conversion table 501 (step S203).

Next, the network control unit 401 creates a storage area reservation response frame (see FIG. 4) based on the network protocol in the buffer 311 (step S204). In the storage area reservation response frame, the source port number of the received storage area reservation request frame is set to the own apparatus port number, the destination port is sent to the central processing unit 101, and a command (storage area reservation) is sent as a response (storage area reservation)
In addition, it can be created by changing the request multiplicity / request speed level to the response speed level.

Next, the network control unit 401 monitors whether the other storage devices 702 and 703 have responded by the arbiter 421 and determines whether the own storage device 701 should respond. When the arbiter 421 confirms that there is no response from the other storage devices 702 and 703, the arbiter 421 sends a storage area reservation response frame on the buffer 411 to the LAN 801 (step S205).

On the other hand, when the required multiplicity in the storage area securing request frame from the central processing unit 101 is 2 and the requested speed level is 1, not only the storage device 701 but also the same requested speed level 1 is stored. The device 702 also secures a storage area. That is, when the request multiplicity is 2, if there is a free storage area in both of the storage devices 701 and 702, the storage devices 701 and 702 respond. In this case, since the storage device 703 is a storage device of the speed level 2, it cannot respond.

Now, the storage device 70 is operated by the arbiter 422.
2 obtains the right to use the LAN 801, the network control unit 402 of the storage device 702
1 performs a process similar to that of the first network control unit 402 to secure a storage area in the storage unit 602 and generate a new entry in the conversion table 502 (step S20).
3).

Then, the network control unit 402 monitors whether the other storage devices 701 and 703 have responded by the arbiter 422 and judges whether the own storage device 702 should respond. And the other storage devices 701 and 703 by the arbiter 422.
When it is confirmed that no response has been received from the LAN, a storage area reservation response frame in the buffer 411 is transmitted to the LAN 801 (step S205).

As described above, even when the required multiplicity is 2,
The storage area reservation response frame is transmitted from only one of the storage devices 701 and 702 in which the storage area is reserved.
Not sent to 1.

In the central processing unit 101, the network control unit 301 receives the storage area reservation response frame via the LAN 801 and temporarily stores it in the buffer 311 (step S103).

The network control section 301
A response (storage area reservation) is extracted from the frame stored on the storage unit 11 to detect that the frame is a storage area reservation response frame, recognize that the previously requested storage area has been reserved, and notify the arithmetic unit 201. (Step S104).

(2) Next, the storage devices 701, 702,
The data write request to the 703 will be described.

Here, an example will be described in which the central processing unit 101 issues a data write request to a storage area secured in both the storage devices 701 and 702.

First, in the central processing unit 101, the arithmetic unit 2
01 transmits a data write request including a source port number, a destination port (multicast), a starting global address, an area size, and data to the network control unit 301 in order to write data to the storage devices 701 and 702.

The network control unit 301 includes the arithmetic unit 20
When a data write request is transmitted from No. 1, a data write request frame (see FIG. 5) is created on the buffer 311 based on the network protocol (Step S).
301), and sends the data write request frame created on the buffer 311 to the LAN 801 (step S301).
302).

In the storage devices 701, 702, and 703, the arbiters 421, 422, and 423 arbitrate requests for securing the right to use the LAN 801.

Now, the arbiter 421 causes the storage device 70
1 obtains the right to use the LAN 801, the network control unit 401 of the storage device 701
, And temporarily stores it in the buffer 411 (step S401).

Next, the network control unit 401 extracts a command (data write), a start global address, an area size, and data from the data write request frame temporarily stored in the buffer 411, and extracts the conversion table 501. It is determined whether or not the storage area of the area size is accessible from the start global address by reference (whether the storage area exists and the status is accessible) (step S40).
2).

If the storage area of the area size is accessible from the start global address, the network control unit 401 converts the start global address into the start local address of the storage unit 601 by referring to the conversion table 501, and Then, data is written to the storage area of the area size from (step S403).

After writing the data in the corresponding storage area of the storage unit 601, the network control unit 401 stores the data write response frame in the buffer 411 (see FIG. 6).
Is created (step S404). The data write response frame uses the source port number of the received data write request frame as its own port number, the destination port as the central processing unit 101, the command (data write) as the response (data write), and no data. Can be created by changing to

The network control unit 40 of the storage device 702
The storage device 702 is also connected to the LAN 8
When the usage right of the storage device 701 is acquired, the same operation as that of the network control unit 401 of the storage device 701 is performed.

As a result, when viewed from the central processing unit 101, data having the same contents is stored in the two storage devices 701 and 702.
Are duplicated and held.

Next, the network control unit 401 of the storage device 701 uses the arbiter 421 to execute the other storage device 702.
When it is confirmed that there is no response from the data write response frame 703 and the data write response frame on the buffer 411,
801 (step S405).

The network control unit 40 of the storage device 702
When the arbiter 422 confirms that there is no response from the other storage devices 702 and 703, the data write response frame on the buffer 412 is transmitted to the LAN 801.
To send to. Therefore, the data write response frame is transmitted only from the storage device that has previously acquired the right to use the LAN 801.

In the central processing unit 101, the network control unit 301 receives the data write response frame via the LAN 801 and temporarily stores it in the buffer 311 (step S303).

The network control unit 301 has a buffer 3
11, a response (data write) is extracted from the frame stored on the memory 11 to detect that the frame is a data write response frame, recognize that the previously requested data has been written to the storage area, and notify the arithmetic unit 201. (Step S304).

(3) Next, a data read request from the central processing unit 101 to the storage devices 701, 702, and 703 will be described.

In the central processing unit 101, the arithmetic unit 201
In order to read data from the storage devices 701 and 702, a data read request including a source port number, a destination port (multicast), a header length, a checksum, a command (data read), a starting global address, and an area size is issued. Network control unit 301
Tell

The network control unit 301 includes the arithmetic unit 20
When a data read request is transmitted from No. 1, a data read request frame (see FIG. 7) is created on the buffer 311 (step S501).

Next, the network control unit 301 transmits the data read request frame in the buffer 311 to the LAN 8
01 (step S502).

In the storage devices 701, 702, and 703, the arbiters 421, 422, and 423 arbitrate requests to acquire the right to use the LAN 801.

When both of the storage devices 701 and 702 hold the same data, the storage device that has acquired the right to use the LAN 801 early outputs read data.

Assuming that the storage device 701 has acquired the right to use the LAN 801 earlier by the arbiter 421, the network control unit 401 receives the data read request frame via the LAN 801, and
11 is temporarily stored (step S601).

Next, the network control unit 401 extracts the starting global address and the area size from the data read request frame temporarily stored in the buffer 411, and refers to the conversion table 501 to store the storage unit 601.
It is determined whether or not a storage area of a storage size is accessible from the start local address corresponding to the start global address (whether the storage area exists and the status is accessible) (step S602). .

If the storage area corresponding to the storage unit 601 is accessible, the network control unit 401 reads data from the storage area of the area size from the start global address of the storage unit 601 (step S603).

Next, the network control unit 401 stores the data read response frame (see FIG. 8) in the buffer 411.
(Step S604). The data read response frame includes a source port number of the received data read request frame as its own port number, a destination port as the central processing unit 101, a command (data read) as a response (data read), and an unused port as a data (read). Can be created by changing to

Next, when the arbiter 421 confirms that there is no response from the other storage devices 702 and 703, the network control unit 401 sends a data read response frame from the buffer 411 to the LAN 801 (step S605).

Even if one of the storage devices 701 storing the data to be read fails, the other storage device 702 performs the same processing and sends a data read response frame to the LAN 801. As a result, even if a failure occurs in one of the storage devices 701 and 702, the computer system does not stop functioning.

In the central processing unit 101, the network control unit 301 receives the data read response frame via the LAN 801 and temporarily stores it in the buffer 311 (step S503).

The network control section 301
11, a response (data read) is extracted from the frame stored on the memory 11 to recognize that the frame is a data read response frame, that the previously requested data has been read, and that the data is read from the data read response frame. It is extracted and passed to the operation unit 201 (step S504).

Thus, in response to the data read request from the central processing unit 101, the corresponding data is obtained by the central processing unit 101.

(4) Next, a storage area release request from the central processing unit 101 to the storage devices 701, 702, 703 will be described.

In the central processing unit 101, the arithmetic unit 201
In order to release the storage area of the storage devices 701, 702, and 703, the source port number, destination port (broadcast), header length, checksum, command (storage area reservation), start global address, and area size are used. Network storage unit 30
Tell 1

The network control unit 301 includes
When the storage area release request is transmitted from the server 1, a storage area release request frame (see FIG. 9) based on the network protocol is created in the buffer 311 (step S70).
1).

Next, the network control unit 301 sends the storage area release request frame created on the buffer 311 to the LAN 801 (step S702).

In the storage devices 701, 702, and 703, the arbiters 421, 422, and 423 arbitrate requests for acquiring the right to use the LAN 801.

Now, the arbiter 421 causes the storage device 70
1 obtains the right to use the LAN 801, the network control unit 401 of the storage device 701
, And temporarily stores it in the buffer 411 (step S801).

Next, the network control unit 401 extracts the command (storage area release), the starting global address, and the area size from the storage area release request frame temporarily stored in the buffer 411, and
It is determined whether or not a storage area corresponding to the storage unit 601 has been secured with reference to 01 (step S802).

If the storage area corresponding to the storage unit 601 is secured, the network control unit 401
In addition to releasing the storage area of the area size from the starting global address in No. 1, the entry consisting of the global address, local address, and status is deleted from the conversion table 501 (step S803).

Next, the network control unit 401 creates a storage area release response frame (see FIG. 10) based on the network protocol in the buffer 411 (step S804). In the storage area release response frame, the source port number of the received storage area release request frame is set to its own port number, the destination port is set to the central processing unit 101, and a command (storage area release) is responded (storage area release).
Can be created by changing to

The arbiter 421 is connected to another storage device 702,
703 monitors whether or not it has responded, and determines whether or not its own storage device 701 should respond.

Now, the storage device 70 is
When the network controller 401 obtains the right to use the LAN 801, the network control unit 401 confirms that the other storage devices 702 and 703 have not responded by the arbiter 421, and then sends the storage area release response frame from the buffer 411 to L.
The message is sent to the AN 801 (step S805).

Network control unit 40 of storage device 702
The storage device 702 is also connected to the LAN 8 by the arbiter 422.
When the usage right of the storage device 01 is acquired, the operation exactly the same as that of the network control unit 401 of the storage device 701 is performed.
1 and 702 are sent to the LAN 801 only.

In the central processing unit 101, the network control unit 301 receives the storage area release response frame via the LAN 801 and temporarily stores it in the buffer 311 (step S703).

The network control unit 301 controls the buffer 3
A response (storage area release) is extracted from the frame stored on the storage unit 11, it is detected that the frame is a storage area release response frame, and it is recognized that the storage area requested earlier has been released and notified to the arithmetic unit 201. (Step S704).

Thus, in response to the storage area release request from the central processing unit 101, the central processing unit 101 can know that the corresponding storage area has been released.

(5) Next, the storage device 7 of the speed level 1
A description will be given of the operation of caching out data from the storage device 01, 702 to the storage device 703 of the speed level 2.

Storage devices 701 and 702 of speed level 1
Performs data copy (securing a storage area and writing data) to the storage device 703 at the speed level 2 and releases the storage area in the storage devices 701 and 702,
A hierarchical storage system that efficiently uses the storage devices 701 and 702 at the speed level 1 can be realized.

Storage devices 701 and 702 of speed level 1
However, as a method of releasing a storage area after copying data to the storage device 703 of the speed level 2, a cache-in and cache-out method used in a cache memory can be applied. Speed level 1 storage device 7
As for the timing at which data cache-out occurs in the storage device 703 of the speed level 2 at 01 and 702, when access to the storage area has not been performed for a predetermined period or more, a new storage area reservation request frame is transmitted. And so on.

For example, the network control unit 401 monitors the access status to the storage area secured in the storage unit 601, and if there is a storage area that has not been accessed from the central processing unit 101 for a predetermined time or more, Data is cached out from the storage device 701 at the speed level 1 to the storage device 703 at the speed level 2 having a lower response speed, and the corresponding storage area of the storage unit 601 is released.

More specifically, the network control unit 401
In order to copy the data of the storage area to be released to the storage device 703 of the speed level 2, first, the source port number is set to the own device port number, the destination port is set to the storage device 703, and the requested speed level is set to the speed level of the own device. A storage area reservation request frame (see FIG. 3) with a speed level 2 lower than 1 is sent to the LAN 801.

Now, the arbiter 423 causes the storage device 70
3 obtains the right to use the LAN 801, the storage device 70
3 receives the storage area reservation request frame via the LAN 801 and
3 temporarily (step S1001).

Next, the network control unit 403 extracts a command (storage area reservation), start global address, and area size from the storage area reservation request frame temporarily stored in the buffer 413, and
It is determined whether or not there is a corresponding free storage area in the storage unit 603 with reference to the storage unit 603. A storage area of a size is secured, and an entry including a global address, a local address, and a status is generated in the conversion table 503 (step S1002).

Subsequently, the network control unit 403 creates a storage area reservation response frame (see FIG. 4) based on the network protocol on the buffer 413, and
1 (step S1003).

In the storage device 701, when the network control unit 401 receives the storage area reservation response frame via the LAN 801 (step S902), it sends a data write request frame (see FIG. 5) with the destination port set to the storage device 703. Is transmitted to the LAN 801 (step S9).
03).

The storage device 703 is set to L by the arbiter 421.
Upon acquiring the right to use the AN 801, the network control unit 403 of the storage device 703 receives the data write request frame via the LAN 801 and temporarily stores the data write request frame in the buffer 413 (step S 1004).

Next, the network control unit 403 extracts a command (data write), a start global address, an area size, and data from the data write request frame temporarily stored in the buffer 413, and converts the conversion table 501. It is determined whether or not the storage area corresponding to the storage unit 603 is accessible by referring to the storage area. If the storage area of the area size from the start global address is accessible, the storage area of the area from the start local address to the storage area of the area size is determined. Write the data (step S10
05).

After writing the data in the corresponding storage area of the storage unit 603, the network control unit 403 sets the transmission source port number as the port number of the storage device 703 and the destination port as the storage device 701 on the buffer 413. A data write response frame (see FIG. 6) is created, and when it is confirmed by the arbiter 423 that there is no response from the other storage devices 701 and 702, the data write response frame on the buffer 413 is sent to the LAN 801 (step S1006). .

In the storage device 701, the network control unit 401 receives the data write response frame via the LAN 801 and recognizes that the data has been written (step S904).

Finally, the network control unit 401 releases (invalidates) the storage area in which the data of the storage unit 601 was stored, and deletes the corresponding entry in the conversion table 501 (step S905).

The network controller 40 of the storage device 702
In the case where there is a storage area that has not been accessed from the central processing unit 101 for a predetermined time or more, the storage device 70
The same operation as the first network control unit 401 is performed.

Thus, the storage device 7 having a high speed level
01, 702, the free storage area increases, and the central processing unit 10
1 enables a more reliable response to a new storage area reservation request.

(6) Next, the storage device 7 of the speed level 2
A description will be given of the operation of caching data into the storage devices 701 and 702 at the speed level 1 from 03.

In the storage devices 701 and 702, the network control units 401 and 402 monitor the access status to the data cached out to the storage device 703, and when the data is accessed, the storage device 7
From 03, the data is cached in the storage areas of the storage units 601 and 602.

For example, when the network control unit 401 of the storage device 701 accesses data cached out to the storage device 703,
In order to cache data in from the storage unit, first, a storage area is secured in the storage unit 601 and the conversion table 5
01 is generated (step S1101).

Next, the network control unit 401 sets the source port number as its own port number and sets the destination port as the storage device 703 in the data read request frame (FIG. 7).
Is transmitted to the LAN 801 (step S110).
2).

In the storage device 703, the network control unit 403 receives the data read request frame via the LAN 801 and temporarily stores it in the buffer 413 (step S1201).

Next, the network control unit 403 extracts a command (data read), a start global address and an area size from the data read request frame temporarily stored in the buffer 413, and refers to the conversion table 503. Data is read from the storage area of the area size from the start local address of the storage unit 603 (step S1202).

Subsequently, the network control unit 403 stores the data read response frame (see FIG. 8) in the buffer 41.
3 and sends a data read response frame (see FIG. 8) in the buffer 413 to the LAN 801 (step S1203).

In the storage device 701, when the network control unit 401 receives a data read response frame from the storage device 703 via the LAN 801 (step S1).
103), data is extracted from the frame and stored in the previously secured storage area (step S110).
4) Send a storage area release request frame (see FIG. 9) with the destination port set to the central processing unit 101 to the LAN 801 (step S1105).

The network controller 40 of the storage device 703
3 receives the storage area release request frame via the LAN 801 and temporarily stores it in the buffer 413 (step S1204).

Next, the network control unit 403 extracts the command (storage area release), the starting global address, and the area size from the storage area release request frame temporarily stored in the buffer 413, and
03, the storage area of the area size is released from the start global address in the storage unit 603, and
The entry including the global address, the local address, and the status is deleted from the conversion table 503 (step S1205).

Subsequently, the network control unit 403 creates a storage area release response frame (see FIG. 10) based on the network protocol on the buffer 413, and stores the storage area release response frame on the buffer 413 on the LAN 801.
(Step S1206).

In the storage device 701, when the network control unit 401 receives a storage area release response frame from the storage device 703 via the LAN 801 (step S11).
06), it is recognized that the corresponding storage area has been released in the storage device 703 (step S1107).

Network control unit 40 of storage device 702
2 performs exactly the same operation as the network control unit 401 of the storage device 701 when there is access to the data cached out in the storage device 703.

As described above, according to the present embodiment, central processing unit 101 issues storage area reservation request, data write request, data read request, and storage area release request to storage apparatuses 701, 702, and 703. At this time, by using a network protocol of broadcast (broadcast communication) or multicast (selective broadcast communication), a plurality of storage devices 701 and 70 can be transferred by one frame transfer.
2, 703, a storage area can be secured, data can be written, data can be read, and the storage area can be released. Therefore, the enhancement of the reliability of multiplexing of stored data can be realized by using the general method of LAN 801 and a simple configuration. In addition, the overhead due to multiplexing (performance degradation due to dead time) can be reduced.

When the storage devices 701, 702, and 703 having different response speeds are connected to the same LAN 801, the storage device 70 having the high response speed at the speed level 1 is used.
The storage device 703 having a low response speed of the speed level 2 responds to the storage area reservation request, the data write request, the data read request, and the storage region reservation request from the storage devices 701 and 702. , 70
2 and the storage device 703, data can be cached out and cached in. As a result,
Since the use efficiency of the storage areas of the storage devices 701 and 702 at the speed level 1 is increased, and data with a low access frequency is stored in the storage area of the storage device 703 at the lower speed level 2, the storage devices are hierarchized. Can be realized.

In the above embodiment, the speed level 1
In the above description, the number of storage devices 701 and 702 is two and the number of storage devices 703 at the speed level 2 is one. However, there is no logical limitation on the number of storage devices, and the storage devices at each speed level are duplicated. It goes without saying that the above-described triple and quadruple operations can be performed, and that the storage hierarchy level can be multi-layered such as three or four layers.

Also, the central processing unit 101 and the storage device 70
1, 702 and 703 are connected via the LAN 801. Therefore, the storage device can be connected at any time due to the characteristic that the hot-swap of the LAN 801 can be performed. It becomes possible.

[0141]

A first effect of the present invention is that multiplexing of storage devices can be easily realized in a computer system in which a central processing unit and a plurality of storage devices are connected via a LAN. That is. The reason is that, between the central processing unit and a plurality of storage devices, a storage area reservation request frame, a storage area reservation response frame, a data write request frame, a data write response frame, a data read request frame, This is because the read response frame, the storage area release request frame, and the storage area release response frame can be transmitted and received via the LAN by broadcast (broadcast communication) or multicast (selective broadcast communication). That is, there is an advantage that the data can be multiplexed by one frame transfer, and the overhead due to the multiplexing does not occur.

Further, in a computer system in which a central processing unit, a storage device having a high speed level, and a storage device having a low speed level are connected via a LAN, it is possible to easily realize a hierarchy of storage devices. That's what it means.
The reason is that a storage area reservation request frame, a storage area reservation response frame, a data write request frame, a data write response frame, and a data read operation are performed between a storage device having a high speed level and a storage device having a low speed level. This is because a request frame, a data read response frame, a storage area release request frame, and a storage area release response frame can be transmitted and received via the LAN.

Further, by utilizing the characteristic that the LAN can be hot-plugged in and out, a storage device is additionally connected to the LAN, so that the computer system is not stopped.
There is an effect that the storage capacity can be expanded and a storage hierarchy can be added.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a storage system according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the contents of a conversion table in FIG. 1;

FIG. 3 is a diagram illustrating contents of a storage area reservation request frame used in the storage system according to the present embodiment;

FIG. 4 is a diagram exemplifying the contents of a storage area reservation response frame used in the storage system according to the present embodiment;

FIG. 5 is a diagram exemplifying the contents of a data write request frame used in the storage system according to the present embodiment;

FIG. 6 is a diagram illustrating contents of a data write response frame used in the storage system according to the present embodiment;

FIG. 7 is a diagram illustrating the contents of a data read request frame used in the storage system according to the present embodiment;

FIG. 8 is a diagram illustrating the contents of a data read response frame used in the storage system according to the present embodiment;

FIG. 9 is a diagram illustrating the contents of a storage area release request frame used in the storage system according to the present embodiment;

FIG. 10 is a diagram exemplifying the contents of a storage area release response frame used in the storage system according to the present embodiment;

FIG. 11 is a flowchart showing processing when a storage area reservation request is made in the storage system according to the present embodiment.

FIG. 12 is a flowchart showing processing at the time of a data write request in the storage system according to the present embodiment.

FIG. 13 is a flowchart showing processing at the time of a data read request in the storage system according to the present embodiment.

FIG. 14 is a flowchart showing processing at the time of a storage area release request in the storage system according to the present embodiment.

FIG. 15 is a flowchart showing an outline of processing when data is cached out in the storage system according to the present embodiment.

FIG. 16 is a flowchart showing an outline of processing at the time of data cache-in in the storage system according to the present embodiment;

[Explanation of symbols]

 101 Central Processing Unit 201 Arithmetic Unit 301 Network Control Unit 311 Buffer 401, 402, 403 Network Control Unit 411, 412, 413 Buffer 421, 422, 423 Arbiter 501, 502, 503 Conversion Table 601, 602, 603 Storage Unit 701, 702 , 703 Storage device 801 LAN

Claims (6)

[Claims] 1. A central processing unit and a plurality of storage devices are connected to an L
In a computer system connected via an AN, a storage area reservation request frame, a storage area reservation response frame, a data write request frame, a data write response frame, a data read request frame, a data read response frame, and a storage area release based on a network protocol. A storage system characterized by realizing multiplexing and layering of storage devices by transmitting and receiving a request frame and a storage area release response frame by broadcast or multicast via a LAN. 2. The apparatus according to claim 1, wherein the central processing unit and the plurality of storage devices are L
In a computer system connected via an AN, the central processing unit includes a storage area reservation request frame, a data write request frame,
A data read request frame and a storage area release request frame are issued to the plurality of storage devices by broadcast or multicast via the LAN, and the plurality of storage devices secure storage regions from the central processing unit via the LAN. Receives a request frame, a data write request frame, a data read request frame, and a storage area release request frame, and secures a storage area, writes data to the storage area, reads data from the storage area, and releases the storage area. By sending a storage area reservation response frame, a data write response frame, a data read response frame, and a storage area release response frame based on a network protocol to the central processing unit via a LAN, the plurality of storage devices Multiplexing Storage system according to claim. 3. In a computer system in which a central processing unit, a storage unit with a high speed level, and a storage unit with a low speed level are connected via a LAN, the central processing unit secures a storage area based on a network protocol. The request frame, the data write request frame, the data read request frame, and the storage area release request frame
Issue to the storage device with the higher speed level via AN;
The storage device having the higher speed level receives a storage area reservation request frame, a data write request frame, a data read request frame, and a storage area release request frame from the central processing unit via the LAN, and secures and stores the storage area. Writes data to the area, reads data from the storage area, and releases the storage area.
A data write response frame, a data read response frame, and a storage area release response frame are returned to the central processing unit via the LAN, and the access status of the storage area of the own apparatus is monitored, and there is no access for a predetermined time or more. When there is a storage area, a storage area securing request frame and a data write request frame based on a network protocol are issued to the storage device having the lower speed level via the LAN to cache out data, and the storage device having the lower speed level is provided. Issue a data read request frame based on a network protocol and a storage area release request frame to the low-speed storage device via the LAN when the cached-out data is accessed, and cache the data; The speed level is low Storage device receives the storage area allocation request frame, a data write request frame, a data read request frame, and a storage area release request frame via the LAN from the speed level is high memory,
A storage area is secured, data is written to the storage area, data is read from the storage area, and the storage area is released, and a storage area reservation response frame, a data write response frame, a data read response frame, and a By returning a storage area release response frame to the storage device having the higher speed level via the LAN, a hierarchy of the storage device having the higher speed level and the storage device having the lower speed level is realized. Storage system. 4. A central processing unit, a plurality of high-speed storage devices and a low-speed storage device are connected to a LAN.
In a computer system connected via a LAN, the central processing unit broadcasts or multicasts a storage area reservation request frame, a data write request frame, a data read request frame, and a storage area release request frame based on a network protocol via a LAN. Is issued to the plurality of storage devices having high speed levels, and the plurality of storage devices having high speed levels are transmitted from the central processing unit via the LAN to a storage area reservation request frame, a data write request frame, and a data read request. Receiving a frame and a storage area release request frame, securing a storage area, writing data to the storage area,
The CPU reads data from the storage area and releases the storage area, and processes the storage area reservation response frame, the data write response frame, the data read response frame, and the storage area release response frame based on the network protocol via the LAN. In addition to sending back a response to the device, the access status to the storage area of the own device is monitored, and if there is a storage area that has not been accessed for a predetermined time or longer, a storage area reservation request frame based on a network protocol;
And issues a data write request frame to the storage device with the lower speed level via the LAN to cache out the data. When the data that has been cached out to the storage device with the lower speed level is accessed, the network protocol is used. A data read request frame and a storage area release request frame are issued to the storage device having the lower speed level via the LAN to cache the data therein. Receives a storage area reservation request frame, a data write request frame, a data read request frame, and a storage area release request frame from a high storage device via a LAN, and secures a storage area, writes data to the storage area, Read data of
And release the storage area, and transfer the storage area reservation response frame, the data write response frame, the data read response frame, and the storage area release response frame based on the network protocol to the plurality of high-speed storage devices via the LAN. By replying, the multiplexing of the plurality of high-speed storage devices is realized, and the hierarchies of the plurality of high-speed storage devices and the low-speed storage devices are realized. Characteristic storage system. 5. An arithmetic unit for issuing a storage area reservation request, a data read request, a data write request, and a storage area release request to the storage device,
In response to a storage area reservation request, a data read request, a data write request, and a storage area release request, a storage area reservation request frame, a data read request frame, a data write request frame,
5. A network control unit for generating a storage area release request frame on a buffer and transmitting the frame generated on the buffer to a LAN. Storage system. 6. A network control unit including a buffer for temporarily storing frames and an arbiter for arbitrating a request for securing a LAN, a storage unit for storing data, and a storage unit in the storage unit. 5. The storage system according to claim 1, further comprising a conversion table for storing a correspondence between a global address and a local address.